Facebook CEO Mark Zuckerberg held a live fireside chat in Berlin on Thursday morning to discuss some of his company's most innovative projects.

At the end of the interview, the moderator asked Zuckerberg one final question:

"How do you see Facebook in 2025?"

Zuckerberg said by that time, he hopes to see progress in three key areas: Connectivity, AI, and virtual and augmented reality.

In terms of connectivity, Zuckerberg said 3 billion people are currently connected to the internet, but there are 7 billion people in the world.

"I think at the current trend, if there’s no real new breakthrough technologies, we’re on trajectory to connect to another billion people," Zuckerberg said. "So we’ll still be here in 2020 or a little bit afterwards and there’ll be 4 billion people connected in the world, but still almost half the people in the world would not have the opportunities the internet brings. So we hope to really bend that curve, through applying these technologies, working in partnerships with all these folks. I don’t know if we’ll get all seven billion, but maybe five, or closer to six."

In the realm of artificial intelligence, Zuckerberg said the biggest question in the industry relates to "unsupervised learning," where machines can infer what they don't know about and are given no positive or negative reinforcement for offering up any kind of solution. But that's a big problem that will be solved over time; right now, Zuckerberg and company will focus on more immediate problems like improving voice recognition software.

"I did a demo earlier [today] that didn't work, so that'll work in 10 years," Zuckerberg said. "Hopefully it'll work sooner."

He says AI will contribute to some breakthroughs that are currently possible, but have yet to be rolled out. Things like self-driving cars — either fully autonomous cars or just more cars that drive themselves more at a time or brake more often when they sense an issue — and systems that can help doctors diagnose diseases will be in global circulation, Zuckerberg hopes.

The 31-year-old Facebook CEO also talked about the potential for virtual and augmented reality.

"There’s real science questions that still need to get solved to create the experience we all want, which is kind of like the glasses we all wear on a daily basis, not this big set of goggles," he said. "But we’re in the beginning of that industry... it’s going to be really exciting to check in 10 years from now and see where that’s going."

Right now, Facebook is heavily invested in virtual reality, where you're completely immersed in a virtual world — it acquired Oculus VR for $2 billion in March 2014, which will release its first VR headset on March 28. But Facebook is also working on augmented reality like Microsoft's HoloLens, where you can see digital elements in your field of view but you're still looking at the real world. "[Augmented reality is] a bit further out," Zuckerberg said in October.

Zuckerberg says these new reality-bending technologies will take at least 10 years to become a "mainstream big thing" like smartphones, which also took about a decade to reach one billion units sold. But he says Facebook is committed to VR and AR, and the company has the resources to invest around the world and improve research in these emerging technologies.

"I think virtual reality is going to make a big difference for giving everyone the power to share what they care about and helping everyone share in the opportunities of the internet,” Zuckerberg said.